Growing & Winemaking



August 2015
by Laurie Daniels
Doug Fletcher
Doug Fletcher, named vice president of winemaking for the Terlato Wine Group in 2006, discusses closures.

Doug Fletcher began his winemaking career in the mid-1970s at Martin Ray in California’s Santa Cruz Mountains, but for the past three decades the Stags Leap District of the Napa Valley has been his winemaking home. After helping start Steltzner Vineyards in Napa, Calif., he was hired in 1987 as winemaker at Chimney Rock Winery.

The Terlato family became partners in Chimney Rock in 2001 (they now own it), and Fletcher was named vice president of winemaking for the Terlato Wine Group in 2006. In that position, he oversees winemaking at Terlato’s California ventures including Chimney Rock, Rutherford Hill and Terlato Family Vineyards in Napa Valley and Sanford in Santa Barbara, Calif., and for labels such as Seven Daughters and Tangley Oaks. Fletcher is also a consultant to Terlato’s joint venture with Michel Chapoutier in Australia. He’s based at Chimney Rock.

Fletcher, who graduated from the University of Oregon in 1973 with a degree in biology, has served on the board of directors and as president of the Stags Leap District Winegrowers Association and held similar positions with the Napa Valley Wine Technical Group.

Wines & Vines: You had some early experiences with synthetic corks that were less than successful. Please describe what happened.


    California wine producers are looking for ways to conserve water in light of the state’s historic drought, and Terlato Wine Group is no exception. To that end, the company in 2014 started testing new technology for measuring water use by the vines in several vineyards.

    “This new technology developed by Tule Technologies is going to help make irrigation decisions easier,” says Doug Fletcher, Terlato’s vice president of winemaking. “It’s pretty amazing technology. It measures the crop evapotranspiration rate (ETc) directly.” Fletcher notes that previously the only way to measure the ETc directly had been by using a lysimeter, which was expensive and cumbersome.

    “Using the surface-renewal device from Tule is like having a lysimeter in every vineyard,” Fletcher says. “For the first time, I can measure the real plant water use. By using this device in conjunction with soil moisture data, we are starting to get a handle on how much to irrigate.”

    He says he’s discovered that “plants have access to water we hadn’t thought about,” which has allowed reduced water use. “In the past, I guessed at how much to irrigate. Now I know how much water to use.”

Doug Fletcher: The first synthetic cork we experimented with was made of silicone. (It) seemed like a good idea; we used silicone bungs in the barrels. I don’t think it ever got off the ground because no one could make it work in the corker. The silicone cork would bounce when it dropped into the corker jaws.

The first commercial bottling we tried was an early version of Supreme Corq. We tried them when I couldn’t find a cork lot that had an acceptable level of TCA. This was back in the late ’90s. I was tired of finding corked bottles in our own tasting room. What other business would tolerate 5% bad product? So we tried Supreme Corqs on a bottling of Fumé Blanc. It worked fine to start with, but after about 18 months you could start to see a difference in the wine, and by two years the wine had noticeably aged. We have avoided synthetic corks since then.

W&V: Which closures are you currently using?

Fletcher: We still use mostly natural cork. We try to do a good quality-control job, and I think we do see lower TCA rates than in years past. That said, we still find corked bottles in the tasting room. But we use only cork lots that have been tested and have a low haloanisole panel number associated with them.

We also use twin tops from Portocork (which is part of the Amorim Group) on some products, such as Tangley Oaks. I visited Amorim a few years ago and was impressed with all the work they are doing to get rid of TCA. The discs and agglomerate they use are processed to remove as much TCA as possible, and I think you can see the results. We are currently avoiding technical or agglomerated corks. I’m worried about the binder glue coming in contact with the wine. We are currently avoiding DIAM corks for that same reason. Also, DIAM corks contain a plastic, which is a concern to me.

We are using ROTE (roll-on tamper-evident screwcaps) on an increasing number of wines. September Hills, Seven Daughters and Grace Lane would be examples. We have avoided the Saran/tin liner because of reduction problems in the wine. That seems to be a pretty well-documented phenomenon. For some wine styles it fits, but not for what we are doing. Our first screwcap bottlings used the Saranex liner. We used it because it let in about the same amount of air as a natural cork. However, we now have moved to the VinPerfect screwcap. I think their liner construction is state of the art. They give the winemaker the ability to control the oxygen transmission rate (OTR) level and have a consistent OTR level. There are studies that show Saranex liners can have a wide OTR range, which you don’t see with VinPerfect.

W&V: How do you decide which closure to use with a particular wine?

Fletcher: The closure is part of the package look, so that decision is made in concert with our marketing and sales departments. In a perfect world, I personally would use VinPerfect ROTE closures on everything we make. But there are a lot of other considerations that go into the decision, and consumer acceptance is a major one. I think you’ll see more screwcaps on expensive wines as the consumer becomes more comfortable with the concept.

W&V: You’ve done trials with a variety o f screwcap liners. What have you found?

Fletcher: Like most wineries, we started doing closure trials many years ago. We have a trial at Chimney Rock using cork, Saran/tin and Saranex screwcaps on Cabernet Sauvignon and Sauvignon Blanc that goes back to 2006. We have older studies but not as well controlled. For the Sauvignon Blanc, I don’t think there is any question: The Saranex-lined screwcap gave the best results. The last time we tasted the trial, it was everyone’s preference. I don’t think it is as clear-cut with the reds. The cork-finished wine had aged in a very nice way. The Saranex-lined screwcapped wine was fruitier and seemed younger. There was a lively discussion about preference.

We also have a two-year trial at Terlato comparing all the different screwcap liners that were available at the time. The trial is looking at all the VinPerfect liners along with Saran/tin and Saranex. I want to see if there is an ideal OTR for different styles of wine. When I set up the trial, I thought I wanted a liner with the least OTR that didn’t cause reduction. However, after two years I’m not sure that should be the objective. One of the wines with a VinPerfect liner that lets in more air than a cork had developed more complexity without any apparent oxidation. So maybe wines for early consumption could be bottled using this kind of liner. Ask me the question again in five years—maybe I’ll know by then.

W&V: Do you need to adjust your sulfur dioxide additions?

Fletcher: No, you don’t need to adjust SO2 levels, but VinPerfect screwcaps give you the opportunity to consider it. But before you consider changing SO2 levels, you need to make sure you have removed most of the oxygen from the headspace. There is a lot more headspace in a screwcapped bottle than a corked bottle, so you need to make sure it isn’t full of oxygen. The only way we have found to solve that problem is by using a liquid nitrogen drop system from Chart (Industries) Liquid Nitrogen Dosing between the filler and capper. Once you have solved that problem, you can consider different levels of SO2 in the wine. If you use a screwcap liner with a low OTR, why not lower the free SO2? The liner will allow less oxygen into the bottle, so maybe you can get away with less SO2 to preserve it. However, we haven’t played with it much ourselves.

A resident of the Santa Cruz Mountains, Laurie Daniel has been a journalist for more than 35 years. She has been writing about wine for publications for more than 21 years and has been a Wines & Vines contributor since 2000.

Currently no comments posted for this article.